Head and neck cancers are a major cause of morbidity and mortality worldwide, and comprise a group of related cancers originating from the aerodigestive tract, and may involve the oral cavity, the lips, pharynx, larynx, nasal cavity, and paranasal sinuses. Cancer of the esophagus is also included among the head and neck cancers. The incidence of the specific types of head and neck cancer vary greatly throughout the world. For example, although rare in other regions, there is a high incidence of nasopharyngeal carcinoma, a human squamous cell cancer, in Southeast Asia and North Africa. The majority of head and neck cancers are squamous cell carcinomas.
Treatment of head and neck cancer may involve surgery to remove the cancer or radiotherapy and/or chemotherapy to destroy the cancer cells. Radiotherapy or radiation therapy remains the primary treatment for head and neck cancer. Radiotherapy uses high-energy x-rays given as external beam radiotherapy or internal beam radiotherapy to kill cancer cells or to stop them from growing further. Although radiotherapy can affect both cancer cells as well as normal cells, but normal cells are better able to resist or recover from the effects. The area of treatment for head and neck cancer varies, and may involve, for example, the back of the throat, as well as the lymph glands in the neck. The treatment is planned carefully to ensure that the rays are targeted precisely onto the cancerous area, and to do as little harm as possible to the surrounding healthy tissues and minimize side effects such as dry mouth (xerostomia) and inflamed mucous membranes (mucositis). Other side effects from poorly directed radiation include dental decay (caries) and death of bone tissue (osteoradionecrosis).
If the patient can be accurately positioned for repeat sessions of radiotherapy, then side effects may be minimized. It is therefore necessary to perform each session of radiotherapy with the patient in an identical position. This can be problematic for the radiotherapy to tumors in the head and neck areas because the patient's lower jaw and tongue are inclined to change position even when the head is held securely.
In order to enable the affected area to be held in the same precise position for treatment, a mask or shell is molded for a patient that is used in combination with a mouthpiece to immobilize the patient and prevent unnecessary exposure of normal tissue to radiation. The mouthpiece is used to depress the patient's tongue onto the floor of the patient's mouth. This helps minimize the movement of the patient's tongue and jaw during the radiation procedure. Traditional mouthpieces are made of contoured wax or are molded to fit the patient's mouth. Among the disadvantages of wax mouthpieces, they must be molded individually for each patient, and may change shape depending on the storage temperature or the temperature inside the patient's mouth. The present mouthpiece is designed to be used quickly and with ease, and to be adjustable depending on the shape of the patient's and the patient's individual bite profile.
Therefore, it is an object of the present invention to provide a device for reducing movement or immobilizing the patient's tongue and to open the patient's jaw during treatment.
It is also an object of the present invention to provide a device that suppresses the tongue with reduced or minimal contact with the tongue.
It is also an object of the present invention to provide a device that permits radiation to pass through the device to reduce effects on surrounding tissue.
It is also an object of the present invention to provide a device for head and neck radiotherapy that is adjustable to accommodate a patient's bite profile and mouth size.